In my experience and research, the MSRP can be very inflated depending upon the dealership and there can be room for negotiating a price.
With a unit one to four years-old, there is considerable depreciation, almost like a buying a new vehicle and trying to sell a year or so later.
If you a planning to buy a used unit, without a trade-in, you will save more money. Go to the NADA website, which will give you a general idea of value:
http://www.nadaguides.com/RVs/Travel-Trailers-5th-WheelsAlso, do not accept the price listed for the unit, put in an offer a few thousand dollars lower. The salesperson will usually go to the sales manager (it is a game they play) and tell you he will see what he can do. You can haggle back and forth for awhile. But in the end, the dealership has their bottom line price and you have to decide if that is what you want to pay or just walk away.
Good luck!